This has been a recurring issue for me. Every time there's a new release of DLS, vs-code shows a "Upgrading DSL" notification with an in-progress indicator, but the notification never goes away and the upgrade never completes.

To complete an upgrade, I have to quit vs-code and delete all the directories under ~/.dub/packages/.bin/. After starting vs-code again, DLS installs correctly.

If it helps to diagnose the issue, for this current release under ~/.dub/packages/.bin/ I have a dls-v0.25.13 directory and a dls-v0.25.14 directory. The latter directory is empty. dis-latest points to dls-v0.25.13.

I'm on macOS Mojave 10.14.6 although the same issue has happened to me on earlier versions of macOS too.